September 3, 2012 - Volcano Voyeur

Volcano Voyeur Trailing the Voyager 2 spacecraft off the launch pad by two weeks, Voyager 1’s faster flight path brought it to its targets (Jupiter and Saturn) months ahead of Voyager 2. The mission, which began thirty-five years ago this week, was only the third time a spacecraft had visited Jupiter. Pioneer 10 and 11 had blazed the trail to the gas giant in 1973 and 1974, and the images and other data they returned set the stage for the more sophisticated Voyager 1 flyby in 1979. Among Voyager 1’s most startling discoveries was the first observation of extraterrestrial volcanos. In this Voyager 1 image of Io, one of Jupiter’s four largest moons, the volcanic plume from the Pele volcano rises 300 kilometers (190 miles) above the surface, and the plume fallout covers an area the size of Alaska.